The present invention relates to a method of cutting out semiconductor devices of very small size, mounted on an integrated gold dissipator. The semiconductor devices concerned by the invention are essentially diodes, produced collectively on a semiconductor material wafer: they are separated into discrete elements, in accordance with the invention, by chemically cutting out the wafer.
The diodes concerned by this chemical cutting out process may be of different types: junction, Schottky, PIN, IMPATT diodes . . . ; etc, and be formed on silicon or on materials of the III-V familes such as GaAs or InP for example. It should be understood by very small size that the chips of each diode have sides of about 200 microns; these are then essentially ultrahigh frequency diodes, although the method can be applied to low power low frequency diodes and so of small size.
Some applications require each diode to have an integrated gold base which serves as heat dissipator. This base is fixed to a good electric and heat conducting material, which is the heat sink properly speaking.
Up to now the formation of such diodes has been obtained by a collective process, but the final separation of each discrete component has been achieved by mechanical cutting out. In fact, cutting out using a laser ray is not possible because of the base. Mechanical cutting out using cutting blades is then used but remains very delicate since the chips have sides of about 200 microns: it is a very precise, long and consequently expensive operation.